For example, serpentine belt accessory drive systems for vehicle engines are each configured to transmit torque to a plurality of accessories to drive them by wrapping a single drive belt around a crank pulley of the engine and driven pulleys for the accessories.
In such a case, if one of the accessories is disabled and goes down, the brake will be applied to the rotation of the driven pulley for the disabled accessory. However, the drive belt does not stop frictional engagement with the driven pulley. This impedes the traveling of the drive belt, which may inhibit appropriate torque transmission to the other accessories or may break the drive belt.
Patent Document 1 discloses, as a solution to the above problem, a belt drive system in which a torque limiter is disposed in a torque transmission path between an input shaft for a variable displacement compressor serving as an accessory and a driven pulley coaxially disposed on the input shaft to allow frictional engagement between an input member connected to the driven pulley for unitary rotation and an output member connected to the input shaft for unitary rotation. According to this technique, when the compressor locks and the load reaches a torque limit, the torque limiter operates to release the frictional engagement between the input and output members to stop torque transmission from the driven pulley to the input shaft.
Patent Document 1: Published Japanese Patent Application No. 2000-356226 (Page 3 and FIG. 1)